hdu 3415 Max Sum of Max-K-sub-sequence【单调队列】

#include<iostream>
#include<cstdio>
using namespace std;
const int maxn=100000+10;
int sum[maxn<<1],que[maxn<<1];
void read(int &d)
{
char ch;bool flag=0;
while(ch=getchar(),(ch>'9'||ch<'0')&&ch!='-');
ch=='-'?d=0,flag=1:d=ch-48;
while(ch=getchar(),ch<='9'&&ch>='0') d=d*10+ch-48;
if(flag) d=-d;
}
int main()
{
int t,n,k;
read(t);
while(t--)
{
read(n),read(k);
for(int i=1;i<=n;i++) read(sum[i]),sum[i]+=sum[i-1];
for(int i=n+1;i<n+k;i++) sum[i]=sum
+sum[i-n];
int head=0,rear=-1,maxs=1<<31,start,end;
for(int i=1;i<n+k;i++)
{
while(head<=rear&&sum[que[rear]-1]>sum[i-1]) rear--;
que[++rear]=i;
while(que[rear]-que[head]>=k) head++;
if(sum[i]-sum[que[head]-1]>maxs)
maxs=sum[i]-sum[que[head]-1],start=que[head],end=i>n?i-n:i;
}
printf("%d %d %d\n",maxs,start,end);
}
return 0;
}